The present invention relates to a plate changing apparatus for supplying a new plate to a plate cylinder and recovering an old plate from the plate cylinder.
A plate changing apparatus of this type is disclosed in Japanese Patent Laid-Open No. 2001-80041. In the plate changing apparatus disclosed in this reference, a plate holding unit for holding a new plate has an old plate storing section for storing an old plate removed from a plate cylinder. In a conventional plate changing apparatus, upon a swing motion of the plate holding unit, when the new plate moves to a plate feed position where it can be fed to the plate cylinder, the old plate removed from the plate cylinder is stored in the old plate storing section.
In the conventional plate changing apparatus described above, as the old plate storing section for storing the old plate removed from the plate cylinder is provided in the plate holding unit, the plate holding unit becomes large in the sheet convey direction. An increase in gap between printing units is limited due to the limitation in the installation space and because the tension to the web may become stable. Hence, when the plate becomes large or the plate holding unit becomes large, the operation of extracting the old plate from the plate holding unit arranged in the space between the printing units becomes cumbersome.
Since the old plate storing section is formed in the plate holding unit, a driving unit for storing the old plate must also be incorporated in the plate holding unit in addition to the old plate storing section, and accordingly the plate holding unit itself also becomes large and heavy. As a result, the driving unit for swinging the plate holding unit also becomes large, making it impossible to downsize the apparatus.